pjproject: Stack-based Buffer Overflow
CVE-2026-57162 is a critical-severity stack-based buffer overflow vulnerability in pjproject from Pjsip, with a CVSS 3.1 base score of 9.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected pjproject versions: < a1b707c0c9b0506faf2a8a438b60f11ffd6a6fd9. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.64% chance of exploitation within 30 days, higher than 51% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of pjproject you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Pjsip | pjproject | < a1b707c0c9b0506faf2a8a438b60f11ffd6a6fd9 | Not stated |
| Teluu | Pjsip | 2.17 and earlier | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 8.8 | High | CNA (github.com) |
| CVSS 3.1 | 9.1 | Critical | NVD |
Official description
PJSIP is a free and open source multimedia communication library written in C. Prior to commit a1b707c, a stack buffer overflow exists in the SRTP/SDES media transport when processing a=crypto attributes during SDP offer/answer (sdes_encode_sdp() in transport_srtp_sdes.c). This affects applications with SRTP enabled (use_srtp optional or mandatory, using SDES keying). During media negotiation, the crypto attributes from the remote SDP are collected into a fixed-size array without bounding their number; a remote peer that includes an excessive number of a=crypto attributes in a single media description can write past the end of that array on the stack. This is reachable from an incoming SIP INVITE during offer/answer, before application-level authentication. Impact may range from unexpected application termination to control flow hijack/memory corruption. Applications that do not enable SRTP are not affected. This issue has been patched via commit a1b707c.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Stack-based Buffer Overflow
The product writes past the end of a buffer that was allocated on the stack.
How developers prevent this class of flaw
- Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.
- Use an abstraction library to abstract away risky APIs. Not a complete solution.
- Implement and perform bounds checking on input.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Other vulnerabilities in pjproject
- 7.4 High severity
- 7.1 High severity
- 9.1 Critical severity
- 8.2 High severity
- 7.5 High severity
- 7.5 High severity
Recent Stack-based Buffer Overflow vulnerabilities
- 9.8 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
- 7.7 High severity
Spotted an error? Tell us.