CVE-2025-13034: No QUIC certificate pinning with GnuTLS
Vulnerability summary
CVE-2025-13034 is a medium (CVSS 5.9) Improper Certificate Validation vulnerability in curl. EPSS estimates a 0.24% chance of exploitation in the next 30 days, higher than 15% of scored vulnerabilities.
Not severe (CVSS 5.9, network access); no exploitation reported by the 5 checked sources
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 3 · Related 1Timeline
- 08-01-2026PublishedVulnerability first disclosed.
- 15-09-2026Last modifiedVulnerability information updated.
Description
When using `CURLOPT_PINNEDPUBLICKEY` option with libcurl or `--pinnedpubkey` with the curl tool, curl should check the public key of the server certificate to verify the peer. This check was skipped in a certain condition that would then make curl allow the connection without performing the proper check, thus not noticing a possible impostor. To skip this check, the connection had to be done with QUIC with ngtcp2 built to use GnuTLS and the user had to explicitly disable the standard certificate verification.
CVSS metrics
5 scores · 5 sources · 1 version- OSV · AlpineEcosystem advisory · calculated5.9MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
- OSV · UbuntuEcosystem advisory · calculated5.9MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
- OSV · DebianEcosystem advisory · calculated5.9MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
- NVDNIST5.9MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
EPSS trend
Probability
0.24%
Chance of exploitation in the next 30 days
Percentile
15%
Versus all other CVEs
30-day change
No change 0.00 pp
From 0.24% on 04-10-2026
Known exploited
Compare KEV catalogsNot in the CISA KEV catalog.
Not in the ENISA CNW catalog.
Not in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.
Alpine1 product
- curl≥ 8.8.0 (No fix recorded) | ≥ 8.8.0, < 8.14.1-r3 | ≥ 8.8.0, < 8.14.1-r4
Curl1 product
- curl≥ 8.8.0, < 8.14.2 | ≥ 8.15.0, < 8.16.1 | ≥ 8.17.0, < 8.18.0 | ≥ 3210101088dfa3d6a125d213226b092f2f866722, < 3d91ca8cdb3b434226e743946d428b4dd3acf2c9 | 8.17.0 | 8.16.0 | 8.15.0 | 8.14.1 | 8.14.0 | 8.13.0 | 8.12.1 | 8.12.0 | 8.11.1 | 8.11.0 | 8.10.1 | 8.10.0 | 8.9.1 | 8.9.0 | 8.8.0
Debian1 product
- curl< 8.14.1-2+deb13u3 | < 8.18.0~rc2-1
Haxx1 product
- curl≥ 8.8.0, < 8.18.0
Ubuntu1 product
- curl< 8.14.1-2ubuntu1.1
5 vendors · 5 products
References
7 links- curl.se/docs/CVE-2025-13034.jsonVendor Advisory